Abstract

Objective: A small but significant proportion of patients with major depressive disorder (MDD) report mild manic symptoms which are below the diagnostic threshold for a hypomanic episode.

Method: We tested for an association between sub-threshold manic symptoms and clinical outcome in almost 600 patients with recurrent MDD who also had no known family history of bipolar disorder.

Results: 9.6% of this large sample had a life-time history of sub-threshold manic symptoms. These patients were significantly more likely to have a history of poor response to antidepressants (OR 2.84; 95% CI 1.23–6.56; P < 0.02) and more likely to have experienced psychosis (OR 2.07; 95% CI 1.05–4.09; P < 0.04). They had also experienced more depressive episodes on average (P = 0.006) and were more likely to have been admitted to hospital (P < 0.03).

Conclusion: Sub-threshold manic symptoms in patients with recurrent MDD may be a useful clinical marker for poor response to antidepressants and a more morbid long-term clinical course.

8Gianni L. Faedda, Ciro Marangoni, What is the role of conventional antidepressants in the treatment of major depressive episodes with Mixed Features Specifier?, CNS Spectrums, 2017, 22, 02, 120CrossRef